说明:
CREATE TABLE
语法
CREATE TABLE [ IF NOT EXISTS ] table_identifier( col_name[:] col_type [ COMMENT col_comment ], ... )[ COMMENT table_comment ][ PARTITIONED BY ( col_name1, transform(col_name2), ... ) ]
参数
table_identifier
table_identifier
支持三段式:catalog.db.name
。Schemas and Data Types
col_type: primitive_type| nested_typeprimitive_type: boolean| int/integer| long/bigint| float| double| decimal(p,s),p=最大位数,s=最大小数点位数, s<=p<=38| date| timestamp,timestamp with timezone,不支持time和without timezone| string,也可对应Iceberg uuid类型| binary,也可对应Iceberg fixed类型nested_type: struct| list| map
Partition Transforms
transform: identity,支持任意类型, DLC不支持该转换| bucket[N],hash mod N分桶,支持col_type: int,long, decimal, date, timestamp, string, binary| truncate[L],L截取分桶,支持col_type: int,long,decimal,string| years,年份,支持col_type: date,timestamp| months,月份,支持col_type: date,timestamp| days/date,日期,支持col_type: date,timestamp| hours/date_hour,小时,支持col_type: timestamp
示例
CREATE TABLE dempts(id bigint COMMENT 'id number',num int,eno float,dno double,cno decimal(9,3),flag boolean,data string,ts_year timestamp,date_month date,bno binary,point struct<x: double, y: double>,points array<struct<x: double, y: double>>,pointmaps map<struct<x: int>, struct<a: int>>)COMMENT 'table documentation'PARTITIONED BY (bucket(16,id), years(ts_year), months(date_month), identity(bno), bucket(3,num),truncate(10,data));
CREATE TABLE AS SELECT
语法
CREATE TABLE [ IF NOT EXISTS ] table_identifier[ COMMENT table_comment ][ PARTITIONED BY ( col_name1, transform(col_name2), ... ) ][ TBLPROPERTIES ( property_name=property_value, ... ) ]AS select_statement
示例
CREATE TABLE dempts_copyCOMMENT 'table create as select'PARTITIONED BY (eno, dno)AS SELECT * from dempts;
REPLACE TABLE AS SELECT
保留表历史 History 的情况下,用 SELECT 查询的结果生成一个快照 Snapshot 来更新表。
语法
CREATE [OR REPLACE] TABLE table_identifier[ COMMENT table_comment ][ PARTITIONED BY ( col_name1, transform(col_name2), ... ) ]AS select_statement
示例
CREATE OR REPLACE TABLE dempts_replaceCOMMENT 'table create as replace'PARTITIONED BY (eno, dno)AS SELECT * from dempts;
DROP TABLE
语法
DROP TABLE [ IF EXISTS ] table_identifier
ALTER TABLE
变更表语法
ALTER TABLE ... RENAME TO
变更表名称
语法
ALTER TABLE table_identifier RENAME TO new_table_identifier
ALTER TABLE ... SET / UNSET TBLPROPERTIES
更新/删除数据表属性
语法
-- SET 更新属性配置ALTER TABLE table_identifierSET TBLPROPERTIES (property_name=property_value, ...)-- UNSET 删除属性配置ALTER TABLE table_identifierUNSET TBLPROPERTIES (property_name, ...)
示例
-- SET 更新属性配置ALTER TABLE dempts SET TBLPROPERTIES ('read.split.target-size'='268435456');-- UNSET 删除属性配置ALTER TABLE dempts SET TBLPROPERTIES ('read.split.target-size'='268435456');
ALTER TABLE ... WRITE ORDERED BY
设置表数据插入时的排序方式
语法
ALTER TABLE table_identifierWRITE [LOCALLY] ORDERED BY{col_name [ASC|DESC] [NULLS FIRST|LAST]}[, ...]
示例
ALTER TABLE dempts WRITE ORDERED BY category, id;-- use optional ASC/DEC keyword to specify sort order of each field (default ASC)ALTER TABLE dempts WRITE ORDERED BY category ASC, id DESC;-- use optional NULLS FIRST/NULLS LAST keyword to specify null order of each field (default FIRST)ALTER TABLE dempts WRITE ORDERED BY category ASC NULLS LAST, id DESC NULLS FIRST;-- To order within each task, not across tasksALTER TABLE dempts WRITE LOCALLY ORDERED BY category, id;
ALTER TABLE ... WRITE DISTRIBUTED BY PARTITION
修改分区表的数据分配策略
语法
ALTER TABLE table_identifierWRITE DISTRIBUTED BY PARTITION[ LOCALLY ORDERED BY{col_name [ASC|DESC] [NULLS FIRST|LAST]}[, ...]]
示例
ALTER TABLE dempts WRITE DISTRIBUTED BY PARTITION;ALTER TABLE dempts WRITE DISTRIBUTED BY PARTITION LOCALLY ORDERED BY id;
ALTER TABLE COLUMNS
变更字段语法
ALTER TABLE ... ADD COLUMNS
新增多个字段
语法
-- 新增多个字段ALTER TABLE table_identifierADD COLUMNS (col_name col_type [COMMENT col_comment], ...)-- 新增单个字段ALTER TABLE table_identifierADD COLUMN col_name col_type [COMMENT col_comment][FIRST | AFTER target_col_name]
示例
-- 新增多个字段ALTER TABLE demptsADD COLUMNS (new_column_1 string comment 'new_column_1 docs',new_column_2 int comment 'new_column_2 docs');-- 新增单个字段ALTER TABLE demptsADD COLUMN new_column_3 string comment 'new_column docs';
ALTER TABLE ... RENAME COLUMN
变更字段名称
语法
ALTER TABLE table_identifierRENAME COLUMN old_column_name TO new_column_name
ALTER TABLE ... ALTER COLUMN
变更字段类型/备注信息
语法
ALTER TABLE table_identifierALTER COLUMN col_name{TYPE new_col_type | COMMENT col_comment}
目前Iceberg TYPE 变更,仅支持字段类型安全扩展:
int/integer -> long/bigint
float -> double
decimal(P,S) -> decimal(P2,S),其中P2 > P,即精准度提升
示例
ALTER TABLE dempts ALTER COLUMN new_column_2 TYPE bigint;ALTER TABLE dempts ALTER COLUMN new_column_2 comment 'alter docs';
ALTER TABLE ... DROP COLUMN
删除表字段
语法
ALTER TABLE table_identifier DROP COLUMN column_name
ALTER TABLE PARTITIONS
ALTER TABLE ... ADD PARTITION FIELD
新增单个分区字段
语法
ALTER TABLE table_identifierADD PARTITION FIELD col_name|transform (col_name) [AS alias]
示例
ALTER TABLE dempts ADD PARTITION FIELD new_column_1;ALTER TABLE dempts ADD PARTITION FIELD bucket(3,new_column_2);
ALTER TABLE ... REPLACE PARTITION FIELD
替换单个分区字段
语法
ALTER TABLE table_identifier REPLACE PARTITION FIELD col_name|transform (col_name) [AS alias]
ALTER TABLE ... DROP PARTITION FIELD
删除单个分区字段
语法
ALTER TABLE table_identifierDROP PARTITION FIELD col_name|transform (col_name);
示例
ALTER TABLE dempts DROP PARTITION FIELD new_column_1;ALTER TABLE dempts DROP PARTITION FIELD bucket(3,new_column_2);
ALTER TABLE ... SET IDENTIFIER FIELDS
添加 identifier fields 属性
语法
ALTER TABLE dempts SET IDENTIFIER FIELDS empno, name
ALTER TABLE .. DROP IDENTIFIER FIELDS
添加 identifier fields 属性
语法
ALTER TABLE dempts DROP IDENTIFIER FIELDS empno, name